From: Steven Rostedt rostedt@goodmis.org
Commit 64cf7d058a00 ("tracing: Have trace_marker use per-cpu data to read user space") made an update that fixed both trace_marker and trace_marker_raw. But the small difference made to trace_marker_raw had a blatant bug in it that any basic testing would have uncovered. Unfortunately, the self tests have tests for trace_marker but nothing for trace_marker_raw which allowed the bug to get upstream.
Add basic selftests to test trace_marker_raw so that this doesn't happen again.
Signed-off-by: Steven Rostedt (Google) rostedt@goodmis.org --- .../ftrace/test.d/00basic/trace_marker_raw.tc | 107 ++++++++++++++++++ 1 file changed, 107 insertions(+) create mode 100644 tools/testing/selftests/ftrace/test.d/00basic/trace_marker_raw.tc
diff --git a/tools/testing/selftests/ftrace/test.d/00basic/trace_marker_raw.tc b/tools/testing/selftests/ftrace/test.d/00basic/trace_marker_raw.tc new file mode 100644 index 000000000000..7daf7292209e --- /dev/null +++ b/tools/testing/selftests/ftrace/test.d/00basic/trace_marker_raw.tc @@ -0,0 +1,107 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0 +# description: Basic tests on writing to trace_marker_raw +# requires: trace_marker_raw +# flags: instance + +is_little_endian() { + if lscpu | grep -q 'Little Endian'; then + echo 1; + else + echo 0; + fi +} + +little=`is_little_endian` + +make_str() { + id=$1 + cnt=$2 + + if [ $little -eq 1 ]; then + val=`printf "\%03o\%03o\%03o\%03o" \ + $(($id & 0xff)) \ + $((($id >> 8) & 0xff)) \ + $((($id >> 16) & 0xff)) \ + $((($id >> 24) & 0xff))` + else + val=`printf "\%03o\%03o\%03o\%03o" \ + $((($id >> 24) & 0xff)) \ + $((($id >> 16) & 0xff)) \ + $((($id >> 8) & 0xff)) \ + $(($id & 0xff))` + fi + + data=`printf -- 'X%.0s' $(seq $cnt)` + + printf "${val}${data}" +} + +write_buffer() { + id=$1 + size=$2 + + # write the string into the raw marker + make_str $id $size > trace_marker_raw +} + + +test_multiple_writes() { + + # Write a bunch of data where the id is the count of + # data to write + for i in `seq 1 10` `seq 101 110` `seq 1001 1010`; do + write_buffer $i $i + done + + # add a little buffer + echo stop > trace_marker + + # Check to make sure the number of entries is the id (rounded up by 4) + awk '/.*: # [0-9a-f]* / { + print; + cnt = -1; + for (i = 0; i < NF; i++) { + # The counter is after the "#" marker + if ( $i == "#" ) { + i++; + cnt = strtonum("0x" $i); + num = NF - (i + 1); + # The number of items is always rounded up by 4 + cnt2 = int((cnt + 3) / 4) * 4; + if (cnt2 != num) { + exit 1; + } + break; + } + } + } + // { if (NR > 30) { exit 0; } } ' trace_pipe; +} + + +get_buffer_data_size() { + sed -ne 's/^.*data.*size:([0-9][0-9]*).*/\1/p' events/header_page +} + +test_buffer() { + + # The id must be four bytes, test that 3 bytes fails a write + if echo -n abc > ./trace_marker_raw ; then + echo "Too small of write expected to fail but did not" + exit_fail + fi + + size=`get_buffer_data_size` + echo size = $size + + # Now add a little more than what it can handle + + if write_buffer 0xdeadbeef $size ; then + echo "Too big of write expected to fail but did not" + exit_fail + fi +} + +test_buffer +test_multiple_writes
Shuah,
After Masami gives an ack, could you take this through your tree.
I don't think it's urgent, but I want to make sure it gets upstream.
-- Steve
On Tue, 14 Oct 2025 14:51:49 -0400 Steven Rostedt rostedt@goodmis.org wrote:
From: Steven Rostedt rostedt@goodmis.org
Commit 64cf7d058a00 ("tracing: Have trace_marker use per-cpu data to read user space") made an update that fixed both trace_marker and trace_marker_raw. But the small difference made to trace_marker_raw had a blatant bug in it that any basic testing would have uncovered. Unfortunately, the self tests have tests for trace_marker but nothing for trace_marker_raw which allowed the bug to get upstream.
Add basic selftests to test trace_marker_raw so that this doesn't happen again.
Signed-off-by: Steven Rostedt (Google) rostedt@goodmis.org
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